Although I'm not an openshift expert, I think you can deeply what is called a custom cartridge, where you can do the install of both wildfly and switchyard.
In upcoming openshift v3, this will be much easier as it will use docker as container format, and will be much easier to create your custom platform deployments.
In the meantime, I recommend you looking at creating the whole cartridge. Of course, this is not available in Openshift Online, AFAIK, but in the other flavors, like openshift enterprise.
Hope it helps.